You mentioned you're in Northern IL. This may or may not be your thing... but going to Wisconsin Dells wouldn't be too terribly far. Yes, I know a lot of attractions there are tourist traps, but not all of them are. My DH and I really enjoy the Wilderness Hotel. It's a huge waterpark hotel, and the wave pool is impressive. There are swim-up bars at the hotel, and you can rent nice cabanas. They have all sorts of activities, like horse-drawn carriage rides, zip-lining, and more.
What you may not know is that Sundara Spa Resort is associated with the Wilderness and on its property. Here is a link:
https://www.sundaraspa.com. My family (all adults) visited Sundara about a year ago and found it extremely relaxing. However, like I said, it's connected to the Wilderness, so you have access to that kind of stuff (water parks, activities), too, if you want it. But if you're looking for a place to just get away from everything and de-stress, I couldn't think of a better place than Sundara. It has won numerous awards from travel publications. It isn't a place you would expect to find in the Dells.
The Dells definitely has golfing, horseback riding, and more. I also like the outlet mall - I always find tons of stuff there. Restaurants are hit and miss. Pretty much all of the big chain restaurants are there. DH and I have found that our favorite restaurant is High Rock Cafe. Just like Sundara, it's not a place you would think to find in the Dells.